Shockproof mechanism, in particular for use in space sector

ABSTRACT

The invention concerns a device forming a mechanism, in particular for use in the space sector, characterised in that it comprises in combination: a material ( 300 ) with low melting point capable of producing a soldering joint, at least heating means ( 400 ), a structure having an architecture with a zone blocked by the low melting point material ( 300 ), capable of being released by liquefying the low melting point material, and means for forced rolling of the low melting point metal ( 300 ) in liquid state, after the heating means ( 400 ) have been activated, to produce a shock absorbing function.

The present invention relates to the field of mechanisms actuated by athermal effect, and particularly but not exclusively to the field ofpyromechanisms, i.e. the field of mechanisms controlled by apyrotechnical effect.

A particular, but non-exclusive, application of the present inventionlies in the field of the space industry, for example on launchers orsatellites, in particular in the form of shears, valves, strap cutters,etc.

Known means actuated by a thermal effect, and in particular knownpyrotechnical means, provide a wide range of options. In particular theypresent considerable potential in terms of amount of energy deliveredper unit on-board mass, and they also present high reliability.

Nevertheless, those mechanisms also suffer from a major drawback: namelythe large dynamic effect induced by operating them.

The levels of shock and vibration often make it impossible for fragileequipment to be used in their vicinity.

The present invention seeks to provide a novel mechanism which does notpresent the above drawback.

In the context of the present invention, this object is achieved byequipment comprising in combination:

a low melting point material:

at least one heater means; and

means suitable for throttling the low melting point material in theliquid state, after the heater means have operated, thereby performing ashock-absorbing function.

According to an advantageous characteristic of the present invention,the low melting point material is a metal.

According to another advantageous characteristic of the presentinvention, the heater means is a highly exothermal pyrotechnicalcomposition.

According to another advantageous characteristic of the presentinvention, the low melting point material is adapted to performsoldering and the device has a structure whose architecture presents azone that is blocked by the low melting point material and that issuitable for being released by liquefaction of the low melting pointmaterial when the heater means are implemented.

Other characteristics, objects and advantages of the present inventionappear on reading the following detailed description and with referenceto the accompanying drawings which are given as non-limiting examplesand in which:

FIG. 1 is a diagram of a structure of the present invention in the formof a linear actuator seen in partial longitudinal axial section; and

FIGS. 2 to 5 show four variant embodiment mechanisms in accordance withthe present invention.

The description begins with the linear actuator structure shown inaccompanying FIG. 1.

The system shown in accompanying FIG. 1 essentially comprises astructure made up of two assemblies 100, 200 capable of moving relativeto each other, a block 300 of low melting point metal, and a highlyexothermal pyrotechnical composition 400.

Specifically, the two assemblies 100 and 200 are capable of moving inrelative translation along the central axis O—O of the structure.

The first assembly 100 is made up of three parts: a body 110, a plug130, and a ring 150.

The body 110 is generally circularly cylindrical about the axis O—O.More precisely, the body 110 possesses a stepped central internalchannel 112. In FIG. 1, the channel 112 is subdivided into threeaxially-juxtaposed sections 114, 116, and 118.

The section 118 presenting the largest inside diameter is adjacent toone end of the assembly 100 and is provided with tapping 119 over afraction of its length. The tapping 119 is complementary to a thread 132provided on the plug 130.

The section 114 presenting the smallest inside diameter is adjacent tothe opposite, second end of the assembly 100. This small section 114 isprovided on its inside surface with an annular groove 115 designed toreceive an O-ring seal 170 for providing sealing between the twoassemblies 100 and 200.

The section 116 of inside diameter that is intermediate between theinside diameters of the above-described sections 114 and 118 is situatedaxially between said two sections.

The plug 130 is generally in the form of a disk extendingperpendicularly to the axis O—O. As mentioned above, the plug 130 has athread 132 complementary to the tapping 119. The plug 130 can thus bescrewed onto the first end of the body 110 in order to close it. Theplug 130 possesses a through axial channel 134, for example a centralchannel. The channel 134 is designed to receive an initiator 180 for thepyrotechnical composition 400, for example an electrical initiator.

The plug 130 is preferably provided with structures, e.g. a series ofoff-center holes 136 to make it easier to turn the plug 130 to ensurethat it is fixed to the body 110.

A step 117 in the form of an annular ring extending transversally to theaxis O—O is defined at the junction zone between the largest diametersection 118 and the intermediate diameter section 116, said ring facingtowards the first end of the assembly 100.

In the embodiment shown in FIG. 1, the second assembly 200 isconstituted by a piston centered on the axis O—O. The outside surface ofthe piston is stepped.

Still more precisely, in the embodiment shown in FIG. 1, the piston 200is stepped to form three sections: 214, 216, and 218.

The smallest diameter section 214 is situated at the second end of thebody 110. Its outside diameter is complementary to the inside diameterof the section 114 of the body 110. The above-mentioned O-ring 170 bearsagainst said outside surface to provide sealing between the twoassemblies 100 and 200.

The largest diameter section 218 of the piston 200 is situated in thevicinity of the first end of the body 110. The outside diameter of thissection 218 lies between the inside diameter of the section 116 and theinside diameter of the section 118 of the body 110.

The section 216 of the piston 200 is situated axially between the twoabove-mentioned sections 214, 218. It possesses an outside diameterlying between the outside diameters of the sections 114 and 116 of thebody 110.

The ring 150 comprises two cylindrical segments 152 and 156 centered onthe axis O—O and interconnected by a central annulus 154 extendingtransversally to the axis O—O.

The cylindrical segment 152 posses an outside diameter lying between theinside diameter of the section 118 of the body and the inside diameterof the intermediate section 116 of the body 110. The inside diameter ofthis cylindrical segment 152 is complementary to the outside diameter ofthe large section 218 of the piston, and it rests against this largesection. The cylindrical segment 152 is situated between the step 117and the internal axial face of the plug 130. The axial length of thecylindrical segment 152 is such that it is prevented from moving, beingclamped between the two above-mentioned elements, when the plug 130 isassembled to the body 110.

The second segment 156 of the ring 150 possesses an outside diameterthat is smaller than the inside diameter of the section 116 and aninside diameter complementary to the outside diameter of the section 216of the piston 200. It rests thereon.

The radial extent of the intermediate annulus 154 over the inside of thecylindrical segment 152 is equal to the radial extent of the segment 218of the piston over the outside of the section 216.

The ring 150 thus operates with the piston 200 to define a chamber 310housing a volume of low melting point metal 300.

This chamber 310 is defined radially outwards by the cylindrical segment152 of the ring 150, radially inwards by the wall of the pistonconstituting the intermediate section 216, axially towards the first endby the large section 218 of the piston, and axially towards the secondend by the intermediate annulus 154 of the ring 150.

The piston 200 is also provided with a central blind chamber 220 whichopens out to the first end of the piston facing the electrical initiator180 and which houses the pyrotechnical composition 400.

The pyromechanism shown in FIG. 1 operates essentially as follows: priorto using the electrical initiator 180 and initiating the pyrotechnicalcomposition 400, the soldered connection constituted by the low meltingpoint metal 300 at the interfaces between the parts 156 and 216 andbetween the parts 152 and 218, and also the solid phase of this metal300 situated inside the chamber 310 provides reliable and effectiveblocking of the structure ensuring that the two assemblies 100 and 200are prevented from moving relative to each other, the ring 150 beingprevented from moving relative to the body 110 and to the plug 130. Itshould be observed that in this position, the small section 214 of thepiston 200 can emerge at least in part to the outside of the assembly100.

When the electrical initiator 180 is powered, that triggers thepyrotechnical composition 400 and thereby rapidly raises the temperatureof the metal 300 sufficiently to cause it to melt, thereby releasing thepiston 200 relative to the assembly 100. The gas coming from thechemical reaction of the pyrotechnical composition 400 causes thechamber 220 to expand and thus moves the piston 200 away from the plug130 in translation along the axis O—O. This displacement of the piston200 reduces the volume of the chamber 310 and thus transfers the lowmelting point metal 300 by throttling it between the adjacent surfacesof the ring 150 and of the piston 200, thereby performing a dampingfunction on the movement.

Thereafter, solidification of the low melting point metal 300reconstitutes a solder connection and finally blocks the device in a newstate in which the piston 200 extends further from the second end of thebody 100 than it did in the initial state.

The person skilled in the art will easily understand that such apyromechanism constitutes an advantageous linear actuator.

Naturally, variant embodiments of the device as described above can beenvisaged.

Firstly, it is possible to provide for the low melting point metal 300to be throttled, not by the interfaces defined between the ring 150 andthe piston 200, but in calibrated bores formed in the ring 150 or in thepiston 200 defining the chamber 310.

Secondly, as described below in greater detail, it is possible toenvisage ensuring that movement of the piston 200 is driven not by thegas resulting from the pyrotechnical composition 400, but under drivefrom an auxiliary drive member, for example a spring element.

The low melting point metal 300 can be thermally insulated from theexternal environment so as to avoid any risk of the metal 300 meltingprior to firing the pyrotechnical composition 400.

To this end, the body 110 and the plug 130 disposed on the outside ofthe chamber 310 are preferably made out of materials presenting poorthermal conduction properties or that are thermally insulating, whilethe piston 200 whose wall forming the intermediate section 216 isinterposed between the pyrotechnical composition 400 and the low meltingpoint metal 300 is preferably made of a metal that is a good conductorof heat.

The metal 300 must also be selected in such a manner as to present amelting or softening temperature that is higher than ambient temperatureso as to ensure that it melts only when the initiator 180 is operated.

The variant embodiment shown in FIG. 2 is described below.

This figure shows a similar structure made up of two assemblies 100 and200 capable of moving in relative translation along an axis O—O, a lowmelting point metal 300, and a pyrotechnical composition 400.

At rest, the low melting point metal 300 prevents the two assemblies 100and 200 from moving relative to each other. When the pyrotechnicalcomposition 400 is fired, the low melting point metal 300 is liquefiedand the gas developed by the pyrotechnical composition 400 drives theassemblies 100 and 200 in relative displacement. The structure is againprevented from moving once the metal 300 has cooled down. In addition,in the embodiment of FIG. 2, the metal 300 is situated in a chamber 310defined between a piston 200 and a ring 150 which is itself preventedfrom moving between a body 110 and a plug 130. More precisely, thechamber 310 is defined by elements of the ring 250 and by elements ofthe piston 200 that are generally L-shaped, each possessing both anaxial segment and a radial segment.

However, compared with the device shown in FIG. 1, the device shown inFIG. 2 presents certain characteristic points, including specificallythe following.

In FIG. 2, the piston 200 is formed by an annular structure which doesnot directly provide the delivered actuator effect, but which controlsan outlet element.

More precisely, this outlet element is constituted by a structure 230capable of being formed, for example, by a nut, a clamp system made upof a plurality of segments, e.g. threaded segments uniformly distributedaround the axis O—O, or any other equivalent means. This element formingan outlet actuator 230 is held captive in an initial rest positionbetween two truncated cones 219, 139 formed respectively on the piston200 and on the plug 130.

In addition, the piston 200 is made up of two parts 202 and 204 whichare assembled together by screw engagement with an interposed O-ring206.

The O-ring 170 is placed in a groove 203 of the part 202 to providesealing between the piston 200 and the body 110 in a manner that iscomparable with that of FIG. 1.

An additional O-ring 172 placed in a groove 137 of the plug 130 providessealing between the plug and the piston 200.

The initiator 180 is placed in a radial passage facing the axis O—Opassing through the wall of the body 110. The initiator 180 thus opensout into an annular chamber 140 containing the pyrotechnical composition400. This chamber 140 is radially defined outwards by the inside wall ofthe body 110, axially beside the second end of the system by atransverse surface of the piston 200, and axially beside the first endand radially beside the inside of the ring 150.

It can also be observed that at the second end, the body 110 presents aplate 1102 directed radially inwards and carrying a sheath 1104 providedwith internal tapping 1106. Such tapping 1106 can receive anycomplementary threaded element for holding temporarily relative to anassociated element held by the tapping 232 of the central element 230 asformed by a nut or by a clamp.

When the initiator 180 is operated, the device shown in FIG. 2 can beused for controlled release of any assembly made up of threaded elementsengaged respectively in the tappings 106 and 232.

In this case also, when the electrical initiator 180 initiates thehighly exothermal pyrotechnical charge 400, the low melting point metal300 initially soldering the ring 150 and the piston 200 together meltsso as to release them for movement. The gas coming from the combustionof the pyrotechnical composition 400 pushes the piston 200 towards thesecond end of the structure. The liquid metal 400 is then throttledthrough the set of clearances formed between the piston 200 and the ring150 so as to provide a damping function controlling the dynamic behaviorof the piston.

The variant embodiment shown in accompanying FIG. 3 is described below.

In this variant, there is again a structure comprising two assemblies100, 200 capable of relative displacement, but initially prevented frommoving by a low melting point metal 300 forming a solder connectionbetween a ring 150 connected to the first assembly and thepiston-forming second assembly 200, together with a highly exothermalpyrotechnical composition 400 associated with an electrical initiator180.

Furthermore, the first assembly 100 is again formed by assemblingtogether a body 110 and a plug 130.

The pyrotechnical initiator 180 is placed in a radial channel passingthrough the wall of the outer body 110 and opening out in an annularchamber 140 defined by the body 110, the ring 150, and in its radiallyinner portion by the outer periphery of the piston 200.

The ring 150 is also connected to the first assembly 100. For thispurpose, it possesses a portion clamped between a shoulder of the body110 and the plug 130.

The annular chamber 310, which contains the low melting point metal 300providing a soldered connection, is situated radially on the inside ofthe chamber 140 and contains the pyrotechnical composition 400, beingdefined by two pairs of L-shaped walls belonging respectively to thering 150 and to the piston 200, each of these two pairs of wallspossessing both a respective wall 154, 218 extending radiallytransversally to the axis O—O and a respective wall 152, 216 extendingaxially parallel to the axis O—O.

In FIG. 3, the chamber 140 containing the pyrotechnical composition 400is radially defined only on the inside by the piston 200, so it will beunderstood that any gas generated by the pyrotechnical composition 400cannot drive movement of the structure.

In this context, in FIG. 3, after the solder 300 has melted, the piston200 is driven towards the second end of the structure by an auxiliarydrive member, for example a spring. In a variant, the piston 200 can bedriven by an element outside the structure shown in FIG. 3, for examplea strap pulling the piston 200 out from the body 110.

As mentioned above, the embodiment shown in FIG. 3 serves, amongst otherthings, to release parts under tension, such as straps, cables, etc.

The variant embodiment shown in FIG. 4 is described below.

This variant has the same general dispositions as shown in FIG. 1 anddescribed above. Nevertheless, it differs from the embodiment describedabove with reference to FIG. 1 in that in FIG. 4, the structure has twopyrotechnical compositions 400, 410, interconnected by a pyrotechnicalrelay 420.

The first pyrotechnical composition 400 communicates with the electricalinitiator 180. It is placed in an annular chamber 220 formed in thepiston 200 close to the metal 300, and more precisely radially on theinside of the chamber 310 defined by the ring 150 and the outerperiphery of the piston 200.

This first pyrotechnical composition 400 is highly exothermal but, whereappropriate, it need not generate much gas. Its function is to melt theadjacent metal 300.

The second pyrotechnical composition 410 is placed in a blind chamber220 formed in a central position in the piston 200 and opening out tothe first end of the structure beside the closure plug 130. Apyrotechnical delay 420 is placed in a radial passage interconnectingthe two chambers 220, 222. Thus, the pyrotechnical composition 410 isfired later than the first pyrotechnical composition 400, after a delaydefined by the time taken to burn the pyrotechnical delay 420. Thesecond pyrotechnical composition 410 is designed to generate a volume ofgas that is sufficient to move the piston 200 as described above withreference to FIG. 1.

By using two pyrotechnical compositions 400, 410 designed respectivelyto melt the metal 300 and to move the piston 200, it is possible toachieve accurate sequential control over the operation of the structure.

The variant shown in FIG. 5 is described below.

This variant also uses the general concepts illustrated in FIG. 1 anddescribed above. However, the variant embodiment shown in FIG. 5 has twopyrotechnical compositions 400, 410 intended respectively to melt themetal 300 and to generate the gas for moving the piston 200. However,unlike FIG. 4, the two pyrotechnical compositions 400, 410 are notinterconnected by a pyrotechnical delay. On the contrary, they areassociated with respective initiators, e.g. electrical initiators 180,182 carried by the plug 130. In this case, sequencing is not controlledby a pyrotechnical effect due to a delay as described for FIG. 4, but byapplying appropriate signals to the respective initiators 180, 182.

Otherwise, in FIG. 5, and comparably to FIG. 4, the highly exothermalfirst pyrotechnical composition 180 is situated adjacent to the metal300 in an annular chamber of the piston 200, while the gas-generating,second pyrotechnical composition 410 is situated in a blind centralchamber 222 of the piston 200.

Naturally the present invention is not limited to the particularembodiments described above, but extends to any variant within thespirit of the invention.

In particular, although the device of the present invention in theembodiments described above essentially constitutes actuation for lineardisplacement along the axis O—O of the device, it is possible in avariant to provide a device which generates forces acting transversallyto the axis O—O, e.g. clamping forces acting by tightening segments thatextend generally axially and that are uniformly distributed around theaxis O—O, and by displacing wedge-shaped or conical means associatedwith the piston 200 that moves.

By way of non-limiting example, the low melting point metal 300 cancomprise:

Bi50/Pb28/Sn22 (for a melting temperature of about 95° C.-110° C.); or

In (for a melting temperature of about 156° C.); or

Sn or Sn85/Zn15 (for a melting temperature of about 200° C.-250° C.); or

Pb82.5/Cd17.5; or

Pb96/Sb4 (for a melting temperature of about 250° C.-300° C.); whereasthe pyrotechnical composition 400 can comprise:

Al+Fe₂O₃; or

Mg+Fe₂O₃; or

Al+CuO; or

Mg+CuO.

Furthermore, in the context of the present invention:

the highly exothermal pyrotechnical composition 400 can be replaced byany suitable equivalent heater means, for example electrical heatermeans; and

the low melting point metal 300 can be replaced by a suitable material,for example paraffin, a eutectic alloy, etc.

What is claimed is:
 1. A mechanism-forming device, in particular forapplication in space, the device being characterized in that itcomprises in combination: a low melting point material (300); at leastone heater means (400); and means suitable for throttling the lowmelting point material (300) in the liquid state, after the heater means(400) have operated, thereby performing a shock-absorbing function,wherein said device further comprises at least two concentric surfaces(154, 216; 152, 218) defining, a set of clearances between them andprovided respectively on parts (150, 200) that are capable of moving inorder to throttle the low melting point material (300) through the setof clearances defined between said concentric surfaces.
 2. A deviceaccording to claim 1, characterized that the fact that the low meltingpoint metal (300) is adapted to perform soldering, and by the fact thatthe device further comprises a structure presenting architecture thatpossesses a zone that is blocked by the low melting point metal (300)and that is capable of being released by the low melting point materialliquefying when the heater means are operated.
 3. A device according toclaim 1, characterized by the fact that the heater means comprise apyrotechnical composition (4.00, 410) designed to generate a volume ofgas that is sufficient to drive relative displacement of the two parts(100, 200) of the device.
 4. A device according to claim 1,characterized by the fact that the chamber (310) housing the meltingpoint material (300) is thermally insulated from the externalenvironment.
 5. A device according to claim 1, characterized by the factthat it has an external element, such as a resilient member of anelement working in traction, suitable for driving relative displacementbetween the two parts (100, 200) of the device after the heater means(400) have been operated.
 6. A device according to claim 1,characterized by the fact that it comprises an outer shell body (110)that is thermally insulating.
 7. A device according to claim 1,characterized by the fact that it includes a piston (200) suitable forbeing moved out from a shell body after the heater means (200) have beenoperated, thereby forming a linear actuator.
 8. A device according toclaim 1, characterized by the fact that it has two parts (100, 230)capable of relative movement for releasing an assembly when the heatermeans are operated.
 9. A device according to claim 1, characterized bythe fact that it includes a nut (230) suitable for being released whenthe heater means are operated.
 10. A device according to claim 1,characterized by the fact that it has a nut (230) made up of a pluralityof segments uniformly distributed around an axis and suitable for beingreleased when the heater means are operated.
 11. A device according toclaim 1, characterized by the fact that it includes a clamp structureconstituted by a plurality of general axially extending segments (194)uniformly distributed around an axis 0—0 and suitable for moving towardsone another during displacement of a piston (200) having an actuatorsurface in the form of a truncated cone, after the heater means (400)have been operated.
 12. A device according to claim 1, characterized bythe fact that it includes an initiator (160) associated with the heatermeans (400).
 13. A device according to claim 1, characterized by thefact that the mechanism constitutes a pyromechanism.
 14. A deviceaccording to claim 1, characterized by the fact that the heater means(400) comprise at least one highly exothermal pyrotechnical composition.15. A device according to claim 1, characterized by the fact that theheater means (400) comprise electrical heater means.
 16. A deviceaccording to any one of claims 1 to 25, characterized by the fact thatthe low melting point material (300) is selected from the groupcomprising paraffin and eutectic alloys.
 17. A device according to claim1, characterized by the fact that the low melting point material (300)is selected from the group comprising paraffin and eutectic alloys. 18.A device according to claim 1, characterized by the fact that the heatermeans comprises two pyrotechnical compositions (400, 410), respectivelyone composition that is highly exothermal and another composition thatgenerates gas, thereby respectively melting the low melting pointmaterial (300) and driving the structure.
 19. A device according toclaim 18, characterized by the fact that the two pyrotechnicalcompositions (400, 410) communicate via a pyrotechnical delay (420). 20.A device according to claim 18, characterized by the fact that the twopyrotechnical compositions (400, 410) are actuated by respectiveinitiators (180, 182).
 21. A mechanism-forming device, in particular forapplication in space, the device being characterized in that itcomprises in combination: a low melting point material (300); at leastone heater means (400); and means suitable for throttling the lowmelting point material (300) in the liquid state, after the heater means(400) have operated, thereby performing a shock-absorbing function,wherein said device comprises at least one calibrated bore opening outinto a chamber containing the low melting point material (300) forthrottling purposes.
 22. A device according to claim 21, characterizedthat the fact that the low melting point metal (300) is adapted toperform soldering, and by the fact that the device further comprises astructure presenting architecture that possesses a zone that is blockedby the low melting point metal (300) and that is capable of beingreleased by the low melting point material liquefying when the heatermeans are operated.
 23. A device according to claim 21, characterized bythe fact that the heater means comprise a pyrotechnical composition(400, 410) designed to generate a volume of gas that is sufficient todrive relative displacement of the two parts (100, 200) of the device.24. A device according to claim 21, characterized by the fact that ithas an external element, such as a resilient member of an elementworking in traction, suitable for driving relative displacement betweenthe two parts (100, 200) of the device after the heater means (400) havebeen operated.
 25. A device according to claim 21, characterized by thefact that the low melting point material (300) is situated in a chamber(310) designed to be reduced in volume during operation of the heatermeans (400).
 26. A device according to claim 21, characterized by thefact that the chamber (310) housing the melting point material (300) isthermally insulated from the external environment.
 27. A deviceaccording to claim 21, characterized by the fact that it comprises anouter shell body (110) that is thermally insulating.
 28. A deviceaccording to claim 21, characterized by the fact that it includes apiston (200) suitable for being moved out from a shell body after theheater means (200) have been operated, thereby forming a linearactuator.
 29. A device according to claim 21, characterized by the factthat it has two parts (100, 230) capable of relative movement forreleasing an assembly when the heater means are operated.
 30. A deviceaccording to claim 21, characterized by the fact that it includes, a nut(230) suitable for being released when the heater means are operated.31. A device according to claim 21, characterized by the fact that ithas a nut (230) made up of a plurality of segments uniformly distributedaround an axis and suitable for being released when the heater means areoperated.
 32. A device according to claim 21, characterized by the factthat it includes a clamp structure constituted by a plurality of generalaxially extending segments (194) uniformly distributed around an axis0—0 and suitable for moving towards one another during displacement of apiston (200) having an actuator surface in the form of a truncated cone,after the heater means (400) have been operated.
 33. A device accordingto claim 21, characterized by the fact that it includes an initiator(160) associated with the heater means (400).
 34. A device according toclaim 21, characterized by the fact that the mechanism constitutes apyromechanism.
 35. A device according to claim 21, characterized by thefact that the heater means (400) comprise at least one highly exothermalpyrotechnical composition.
 36. A device according to claim 21,characterized by the fact that the heater means (400) compriseelectrical heater means.
 37. A device according to any one of claims 1to 25, characterized by the fact that the low melting point material(300) is selected from the group comprising paraffin and eutecticalloys.
 38. A device according to claim 21, characterized by the factthat the low melting point material (300) is selected from the groupcomprising paraffin and eutectic alloys.
 39. A device according to claim21, characterized by the fact that the chamber (310) housing the meltingpoint material (300) is defined by two L shaped structures, eachpossessing both an axially extending wall (152, 216) and aradially-extending wall (254, 218) secured respectively to twoassemblies (100, 200) capable of relative movement.
 40. A deviceaccording to claim 39, characterized by the fact that the chamber (310)housing the melting point material (300) is defined at least in part bya ring (150) secured to a fixed body (110).
 41. A device according toclaim 40, characterized by the fact that the ring (150) is clampedbetween an outer shell body (110) and a closure plug (130).
 42. A deviceaccording to claim 21, characterized by the fact that the heater meanscomprises two pyrotechnical compositions (400, 410), respectively onecomposition that is highly exothermal and another composition thatgenerates gas, thereby respectively melting the low melting pointmaterial (300) and driving the; structure.
 43. A device according toclaim 42, characterized by the fact that the two pyrotechnicalcompositions (400,410) communicate via a pyrotechnical delay (420). 44.A device according to claim 42, characterized by the fact that the twopyrotechnical compositions (400, 410) are actuated by respectiveinitiators (180, 182).
 45. A mechanism-forming device, in particular forapplication in space, the device being characterized in that itcomprises in combination: a low melting point material (300); at leastone heater means (400); and means suitable for throttling the lowmelting point material (300) in the liquid state, after the heater means(400) have operated, thereby performing a shock-absorbing function,wherein the heater means comprise a pyrotechnical composition (400, 410)designed to generate a volume of gas that is sufficient to drive arelative displacement of two parts (100, 200) of the device.
 46. Adevice according to claim 45, characterized that the fact that the lowmelting point metal (300) is adapted to perform soldering, and by thefact that the device further comprises a structure presentingarchitecture that possesses a zone that is blocked by the low meltingpoint metal (300) and that is capable of being released by the lowmelting point material liquefying when the heater means are operated.47. A device according to claim 45, characterized by the fact that itcomprises at least two concentric surfaces (154, 216; 152, 218) providedrespectively on parts (150, 200) that are capable of moving in order tothrottle the low melting point material (300).